Journalists Kirill Radchenko, Alexander Rastorguyev, and Orkhan Dzhemal were killed in the strife-torn African country on Monday.

They were reporting on the so-called Wagner Group, a company that sends Russian mercenaries to hotspots such as Syria and Ukraine and has been described as Moscow's shadow army.

"Today the bodies of the three victims were brought to Russia," the Investigative Committee said in a statement.

It added that the bodies will undergo forensic medical examinations to "establish the cause of death of the Russian citizens".

"Work is continuing to clarify the circumstances of the crime. Friends and other persons that may have any information in connection with the investigation of this crime are being interviewed," the statement said.